Electromagnetic conveying trough for the transport of liquid metals

ABSTRACT

A LIQUID METAL CONVEYOR OF THE INDUCTION TYPE WITH A GRADUALLY ASCENDING LIQUID-METAL TROUGH, HAS THE UPPER END OF THE TROUGH BENT TOWARD THE HORIZONTAL. THIS AVOIDS THE TENDENCY OF LIQUID METAL TO STAGNATE AT THE UPPER END WHERE THE END POLE DIVISION OF THE INDUCTION WINDING TENDS TO PRODUCE A WEAKER ELECTROMAGNETIC FIELD.

Jan. 12, 1971 VON STARCK ETAL 3,554,670

' ELECTROMAGNETIC CONVEYING TROUGH FOR THE TRANSPORT OF LIQUID METALS Filed Nov. 12, 1968 In venfars;

AXEL voN STAfiCt A'ITo RNEV United States Patent "ice 3,554,670 ELECTROMAGNETIC CONVEYING TROUGH FOR THE TRANSPORT 0F LIQUID METALS Axel von Starch, Rernscheid-Luttringhausen, and Friedrich Schnalre, Staatsangehorigkeit, Germany, assignors to AEG-Elotherm G.m.b.H., Remscheid-Hasten, German y Filed Nov. 12, 1968, Ser. No. 774,796 Claims priority, application Germany, Apr. 19, 1968, 1,758,191 Int. Cl. H02h 4/20; B65s 17/46; H03k 45/00 US. Cl. 41750 Claims ABSTRACT OF THE DISCLOSURE A liquid metal conveyor of the induction type with a gradually ascending liquid-metal trough, has the upper end of the trough bent toward the horizontal. This avoids the tendency of liquid metal to stagnate at the upper end where the end pole division of the induction winding tends to produce a weaker electromagnetic field.

The transport of liquid or molten metals by electromagnetic conveying troughs has been proposed in which there is an elongated trough and an inductor on which the trough rests, or which is disposed above the trough or laterally next to it. The inductor employs the principle of the stator of a standard induction motor, cut open around its longitudinal axis so as to project along a plane. Thus the inductor comprises a stack of slotted or toothed laminations and an electrical winding which is inserted in the slots of the laminations. The stack of laminations for the polyphase winding of the inductor is divided into a number of poles and the length of the poles in a longitudinal inductive direction is indicated by the pole pitch.

It is generally desirable, in the actual operation of electromagnetic conveying troughs, to produce a constant transporting force over the entire length of the trough or channel in order to achieve the smoothest possible conveyance of the liquid metal. However, it has been found that the conveying force toward the end of the trough in the area of the last pole division or fraction of the indicator tends to decline linearly and may decline nearly to zero. This phenomenon results, in the actual operation of ascending-trough apparatus, in stagnation of the liquid metal at the upper end and thus to a reduction of the conveying capacity of the apparatus.

An object of the invention, accordingly, is the production of an electromagnetic conveying trough for liquid metals in which a damming up or stagnation of the liquid metal to be conveyed at the upper end of the conveying path is prevented. This is accomplished in accordance with the invention by utilizing an electromagnetic conveying trough which ascends at an angle to the horizontal, but which bends toward the horizontal in the area of the last pole division. The bending may take place abruptly or gradually.

A better understanding of the invention will be afforded by the following detailed description considered in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram, essentially a longitudinal, vertical section of an electromagnetic conveyor for liquid metals in accordance with the invention, and

FIG. 2 is a corresponding diagram of a modified embodiment of the invention.

Like reference characters are utilized throughout the drawing to designate like parts.

In the embodiment illustrated in FIG. 1, a heat-retaining vessel or melting crucible 1 is provided with a linearly ascending electromagnetic conveying trough or channel 2. The addition of molten metal 3 to the crucible 1 fills Patented Jan. 12, 1971 it to such a level that a portion of the molten metal 3 flows into the conveying trough 2. The electromagnetic conveying trough 2 consists mainly of a channel body 4, composed of fireproof material, and an inductor 5". In the embodiment illustrated the inductor 5 is mounted immediately underneath the channel body 4. The inductor 5 is represented as being several pole spans in length and with a final pole division 6 at the upper end.

At the end of the electromagnetic conveying trough 2, for instance in the area of the last pole division 6 of the inductor 5, the inductor 5 as well as the channel body are bent in the direction toward the horizontal. Although the invention is not limited thereto, in the embodiment of FIG. 1 the inductor and the channel body are bent abruptly and lie substantially horizontal at the area of the final pole division 6. In consequence, the conveying elficiency is improved, the conveying capacity and thus also the traveling speed of the molten metal 3, remain nearly constant over the entire length of the trough 4. In order to achieve substantially complete constancy of the conveying force, the conveying trough 2 may be gradually or progressively bent in the area of the pole division 6 for producing a gradual transition of the channel end toward the horizontal.

In cases where the ascent of the conveying trough 2 is very small, or if the inductor 5 is mounted above the channel body 4 or laterally to it, it is sufiicient to bend only the channel body 4 in the area of the last pole division 6 in the direction toward the horizontal. As illustrated in FIG. 2, this is done by gradually reducing the thickness of the fireproof lining of the channel body 4. While the invention has been described as embodied in concrete form and as operating in specific manner in accordance with the provisions of the patent statutes, it should be understood that the invention is not limited thereto, since various modifications will suggest themselves to those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. An electromagnetic conveyor for liquid metal of the type employing an inclined ascending trough and an inductor with a polyphase electrical winding comprising a plurality of successive poles in inductive relation to the trough with an inherently weaker end pole division at the upper end of the trough, the conveyor being characterised by the fact that the trough is formed with a smaller angle of ascent in the area of the upper end pole division.

2. A conveyor as described in claim 1 in which the inductor as well as the trough is formed with a smaller angle of ascent in the area of the upper end pole division.

3. A conveyor as described in claim 2. in which the change in angle of ascent is abrupt.

4. A conveyor as described in claim 2 in which the change in angle of ascent is gradual.

5. A conveyor as described in claim 1 in which the conveying trough is provided with a fireproof lining having a gradual reduction in thickness in the area of the upper end pole division of the inductor, whereby the angle of ascent of the trough is diminished in the area of the upper end pole division.

References Cited UNITED STATES PATENTS 

